Florence and The Machine: Behind the Scenes at Radio City Music Hall Concert

Florence Welch, the lead singer of the indie rock band Florence + the Machine, said the only place she feels comfortable is on the stage, performing.

"It's like, instead of like stage fright, it's more like life-fright," Welch told "Nightline" anchor Cynthia McFadden. "The singing stays the same and then the rest of your life becomes something you have to navigate something different every day."

The 25-year-old, Grammy-nominated singer, known for her hauntingly powerful voice and eclectic outfits, talked with "Nightline" about pretending to be a witch while growing up in South London and how she started out her career wearing "boyish" clothes and thrift store threads.

Prior to the interview, Florence + the Machine performed a sound check of "No Lights, No Lights," one of the group's singles from its latest album, "Ceremonials," at Radio City Music Hall in New York City. Watch a behind-the-scenes sneak peek of the concert here: